JPS63156619A - Electric discharge machine for fine hole - Google Patents

Abstract

PURPOSE:To make a lot of fine holes efficiently machinable, by installing a device, detecting a rate of consumption by machining of an electrode, and also a controlling mechanism which delivers the electrode as much as the specified quantity from an electrode shaft by a command out of this detecting device. CONSTITUTION:A variation of a contact position between an electrode 5 and a workpiece 4 comes to electrode consumption. This electrode consumption is operated by an electrode consumption detection circuit 10, and corresponding to this electrode consumption, a command out of the electrode consumption detection circuit 10 is given to an electrode delivery control circuit 22. And, a pulse motor 18 is rotated as far as the specified angle by a signal out of this control circuit 22, and a moving pin 14 is rotated via a pullet 20, a belt 21 and a pulley 17. The electrode 5 is delivered in order with a support pipe 12 as a guide by rotation of this moving pin 14. That is to say, a pitch size portion of a screw 15 of the moving pin 14 is feedable per rotation of the pulse motor 18. Accordingly, a lot of fine holes can be machined in an effective man ner.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is applicable to inkjet printer nozzles, electron gun apertures used in graphic displays, optical fiber connectors, synthetic fiber nozzles, automobile firing nozzles,
The present invention relates to a micro-hole electrical discharge machining device for electrical discharge machining of micro-holes in resin molding molds, micropress molds, and the like.

Conventional technology In recent years, there has been a strong demand for smaller hole diameters and higher precision in order to improve the performance of the equipment used to make micro holes, as described above.Also, with the expansion of applications, improvements in machining efficiency have been required. Therefore, electrical discharge machining equipment dedicated to micro-hole machining has been developed and put into practical use. As this conventional micro-hole electric discharge machining device, for example, Japanese Patent Laid-Open No. 57-33922, Electric Machining Technology Vol.
8 A621. The configuration described on pages 3 to 6 is known.

Hereinafter, a conventional electric discharge machining apparatus will be explained with reference to FIG.

As shown in FIG. 3, a power source 104 is connected to the electrode 101 and the workpiece 103 immersed in the insulating liquid 102, and the power source 104 applies discharge power to the electrode 101 and the workpiece 103. When electrode 101 descends, electrode 1
o1. Due to the electric discharge between the workpieces 103, the portion of the workpiece 103 facing the electrode 101 is removed by bath melting, and a hole or groove having a value larger than the electric discharge i1ot by the discharge gap 105 is machined. Therefore, the dimensions of the electrode 101 must correspond to the shape to be processed. In the case of micro-hole machining, a thin wire made of tungsten or brass material that has been previously formed to a predetermined diameter is used as the electrode 101, or a thin wire made of tungsten or brass material is processed to a predetermined diameter by means such as reverse discharge forming. and use it.

Next, an electrode holding means used in a conventional micro-diameter electrical discharge machining apparatus will be explained with reference to FIG.

As shown in FIG. 4, the rotating mandrel 106 is formed into a cylindrical shape, and a guide tube 107 made of ceramic is attached to the tip of the rotating mandrel 106.
The base side of a support tube 108 made of ceramic is fixed inside the support tube 108 . An electrode 101 made of a small diameter wire is slidably inserted into the support tube 108 and supported, and the electrode 101 is held in alignment with the center of rotation of the rotating mandrel 106 with high precision. The rear end of the electrode 101 is connected to a rotating mandrel 10.
In the rear side of 6, a holding cylinder 1 made of nickel, etc.
09 and is held in a fixed state. Screws 110 are screwed into the rear side of the rotating mandon 106 from the radial direction, and these screws 110 hold the holding cylinder 109. That is, while the electrode 101 is fixed to the rotating mandrel 106, electrical continuity of the electrode 101 to the outside is ensured by the holding tube 109 and the screw 110.

Problems to be Solved by the Invention However, as the process of melting and removing the workpiece 103 progresses, the electrode 101 is inevitably consumed, although the amount is smaller than the removal of the workpiece 103. This amount of consumption varies depending on the electrode diameter and applied machining energy. When processing micro diameters,
The electrode 101 is normal.

Since a thin wire is used and its strength is inferior, the amount of protrusion from the support tube 108 cannot be increased. Therefore, the value that can be used for machining becomes small, and the electrode consumption determined by the above-mentioned machining conditions occurs, and there is a certain limit to the amount that can be machined.

When machining becomes impossible due to such electrode wear, loosen the screw 110 and manually remove the electrode 101 and holding cylinder 109.
are fed out at the same time, and the screws 110 are tightened again for use.

Therefore, for workpieces that require tens to hundreds of holes to be machined, not only must the electrode 101 be fed out frequently, but the electrical discharge machining apparatus must be stopped each time. , which was a very time-consuming task.

SUMMARY OF THE INVENTION Therefore, the present invention aims to provide a micro-hole electrical discharge machining device that can efficiently machine a large number of micro-holes by automatically feeding out electrodes in accordance with the amount of wear. be.

Means for Solving the Problems and the technical means of the present invention for solving the above-mentioned problems are: a machining tank in which a workpiece is immersed in an insulating liquid; and an electric discharge machining method for the workpiece. an electrode that forms a microhole, an electrode shaft that holds this electrode so that it can be sent out, a power supply that supplies electric power for the discharge generated between the electrode and the workpiece, and a relative position between the electrode and the workpiece. The apparatus is equipped with a driving means for adjusting the distance, a means for detecting the amount of wear of the electrode due to machining, and a control mechanism for feeding out the electrode by a fixed amount from the electrode shaft according to a command from the detecting means.

action The effects of the above technical means are as follows.

That is, when the electrode wears out due to machining of the electrode and the workpiece by electric discharge, the electrode can be automatically fed out.

Example EMBODIMENT OF THE INVENTION Below, one embodiment of the present invention will be described in detail based on the drawings.

FIG. 1 is a partially cut-out side view of a main part showing a micro-hole electric discharge machining apparatus according to an embodiment of the present invention.

In Figure 1, 1 is a processing tank made of insulating material, 2 is a processing tank 1
3 is an insulating liquid placed in the processing tank 1 , and 4 is a workpiece fixed to the platform 2 and immersed in the insulating liquid 3 . 5 is an electrode, 6 is an electrode shaft that holds the electrode 5 so as to be able to be sent out, and 7 is a driving means that drives the electrode shaft 6 and the electrode 5 in the direction of arrow Z, that is, in the thickness direction of the workpiece 4. A machining power source 8 is connected to the electrode 5 and the workpiece 4 and supplies discharge power. 9 is an electrode feeding control mechanism; 10 is the amount of change in the contact position between the electrode 5 and the workpiece 4;
In other words, the electrode consumption detection circuit detects the amount of electrode consumption.
It is connected to the electrode delivery control mechanism 9.

Figure 2 shows the electrode 5, electrode shaft 6, and electrode delivery control mechanism 1.
FIG. 2 is an enlarged partially cutaway side view showing details of 0; As shown in FIG. 2, the electrode shaft 6 is integrally equipped with a guide tube 11 at its tip.
A support tube 12 made of a ceramic material is integrally provided inside the guide tube 11, and an electrode 5 made of a thin wire is slidably inserted into the inside of this support tube 12, and the electrode 5 is placed in the center of the electrode shaft 6 with high precision. Matched and retained. A screw 13 is formed inside the electrode shaft 6, and a screw 15 formed on the outer periphery of the moving pin 14 is screwed into this screw 13.

The rear end of the electrode 5 is press-fitted into a recessed hole 16 formed in the moving pin 14 and fixed therein. Therefore, the electrode 5 can be sent out from the support tube 12 by rotating the moving pin 14. A pulley 17 is attached to the rear protruding end of the movable pin 14, while a pulse motor 1 supported by a pedestal (not shown)
A pulley 20 is attached to the output shaft 19 of 8, and a belt 21 is placed around these pulleys 20 and 17. The pulse motor 18 is connected to an electrode feed control circuit 22, and the electrode consumption amount detection circuit 1 is connected to the electrode feed control circuit 22.
0 is connected.

Next, the operation of the above embodiment will be explained. The electrode 5 is brought close to the workpiece 4 immersed in the insulating liquid 3 in the processing tank 1 by the driving means 7, and a power source 8 is connected to the electrode 5 and the workpiece 4.
A voltage is applied and machining is performed by mutual discharge.

At this time, the contact position between the electrode 5 and the workpiece 4 (processing start point)
is detected by the electrode wear amount detection circuit 10 from the conduction state between the two and stored. When machining at that position is completed,
The workpiece 4 is moved together with the processing tank 1 to the next processing position.

”Then, the above machining operations are repeated.

Here, the amount of change in the contact position between the electrode 5 and the workpiece 4 is the amount of electrode consumption. This amount of electrode consumption is calculated by the electrode consumption amount detection circuit 10, and a command from the electrode consumption amount detection circuit 10 is sent to the electrode delivery control circuit 22 in accordance with the amount of electrode consumption.
The pulse motor 18 rotates by a predetermined angle (pulse) according to the signal from the electrode delivery control circuit 22.
The moving pin 14 rotates via the pulley 20, belt 21, and pulley 17. By this rotation of the moving pin 14, the electrodes 5 are sequentially sent out using the support tube 12 as a guide as described above. In other words, it is possible to feed the movable pin 14 by the pitch dimension of the screw 15 per one rotation of the pulse motor 18. The electrode 5 may be sent out every time one hole is machined, or when the amount of wear of the electrode 5 exceeds a predetermined value.

Note that electrical discharge machining may be performed with the electrode 5 in either a rotating state or a stopped state. Alternatively, the workpiece 4 side may be driven with respect to the electrode 5.

Effect of the invention As is clear from the above description, according to the present invention.

A voltage for forming microholes in a workpiece by electrical discharge machining is supported so as to be sent to an electrode shaft, and the amount of electrode consumption due to machining is detected by an electrode consumption amount detection means.

Since the electrode can be automatically fed out in response to the electrode feeding control consumption monitoring based on the commands of the detection means, it is possible to effectively process a large number of fine holes.

[Brief explanation of the drawing]

Figures 1 and 2 show a micro-hole electric discharge machining apparatus according to an embodiment of the present invention. Figure 1 is a partially cutaway enlarged view of the main part, and Figure 2 is an electrode, an electrode shaft, and an electrode feeding control mechanism. FIG. 3 is a sectional view of a main part of a conventional electric discharge machining apparatus, and FIG. 4 is a sectional view showing a conventional electrode holding means. 1... Processing tank, 3... Insulating liquid, 4... Workpiece,
5... Electrode, 6... Electrode shaft, 7... Drive means, 8
... Power source, 9... Electrode delivery control mechanism, 10...
・Electrode consumption amount detection circuit, 18...Pulse motor, 22
... Electrode delivery control circuit. Name of agent: Patent attorney Toshio Nakao and 1 other person
1rl! J Figure 3 Electrode Figure 4

Claims (1)

[Claims] A machining tank in which a workpiece is immersed in an insulating liquid, an electrode for forming a microhole in the workpiece by electrical discharge machining, an electrode shaft that holds the electrode so that it can be sent out, and the electrode and the workpiece. A power supply for supplying electric power for electric discharge generated between objects, a driving means for adjusting the relative distance between the electrode and the workpiece, a means for detecting the amount of wear of the electrode due to machining, and a command for the detecting means. A micro-hole electric discharge machining device comprising: a control mechanism for feeding out the electrode by a certain amount from the electrode shaft.